Positive sinker control for multifeed knitting machines

ABSTRACT

This sinker control means provides positive inward and outward radial movement of the sinkers at each knitting station of a circular multifeed hosiery knitting machine to maintain the sinkers under accurate control at all times. This sinker control eliminates the use of a sinker spring band of the type which is normally utilized in the control of the operation of the sinkers. A more gradual inward and outward movement of the sinkers is provided by this sinker control so that the machine may be operated at a higher rate of speed and the positive control of the sinkers produces a more uniform and clearer hosiery fabric.

United States Patent Minton [72] Inventor: Clarence W. Minton, Nashville, Tenn.

[73] Assignee: Americal Corporation, Henderson, NC.

[22] Filed: Oct. 16, 1970 [21] App1.No.: 81,196

[52] US. Cl. ..66/l08 R' [51] Int. Cl. I 4 1 ..D04b 15/24 [58] Field of Search ..66/107, 108 R, 108 A, 104, 66/42 [56] References Cited UNITED STATES PATENTS 1,467,691 9/1923 Scott ..66/108 R 2,289,052 7/1942 Seligman ..66/107 X 464,313 12/1891 Cook ..66/108 R 806,293 12/1905 Rowe ...66/108 R 1,546,057 7/1925 Bosworth ..66/108 R POSITIVE SINKER CONTROL FOR MULTIFEED KNITTING MACHINES [451 Apr. 25, 1972 FOREIGN PATENTS OR APPLICATIONS Primary Examiner-Wm. Carter Reynolds Att0rneyParrott, Bell, Seltzer, Park & Gibson 57 ABSTRACT This sinker control means provides positive inward and outward radial movement of the sinkers at each knitting station of a circular multifeed hosiery knitting machine to maintain the sinkers under accurate control at all times. This sinker control eliminates the use ofa sinker spring band of the type which is normally utilized in the control of the operation of the sinkers. A more gradual inward and outward movement of the sinkers is provided by this sinker control so that the machine may be operated at a higher rate of speed and the positive control of the sinkers produces a more uniform and clearer hosiery fabric.

13 Claims, 11 Drawing Figures PATENTED APR 2 5 I972 SHEET 1 BF 3 INVENTOR. CLAEENCE- W. MWTON www A TTOR NE YE.

PATENT EU APR 2 5 I972 SHEET 2 BF 3 INVENTORI CLARENCE: W. M l NTON WW a ATTORNEY5 PATfNTl-imms I972 SHEET 3 OF 3 INVENTOR. CLAREMQE-W. VMNTQN M MIME/6% Mug/1m ATTORNEYS POSITIVE SINKER CONTROL FOR MULTIFEED KNITTING MACHINES This invention relates generally to a positive sinker control means for a multifeed hosiery knitting machine and more particularly to such a sinker control for use with fine gauge ladies hosiery knitting machines having on the order of about 400 needles in the needle cylinder.

The first fine gauge ladies hosiery machines were all of the type having a single knitting station. In order to increase production, the number of knitting stations has been increased and there are now circular hosiery knitting machines having eight and 12 feeds around the needle cylinder. At each of these knitting stations, the sinkers are moved outwardly and the yarn forms stitch loops as the needles are lowered and then the sinkers are moved inwardly as the stitch loops are formed to cast off the shed stitch loops as the needles are again raised. Since the needle cylinder is only about 4 inches in diameter, the knitting stations are closely spaced and it is necessary to move the sinkers in and out in a reduced space and at a much faster rate. Also, the control of the radial movement of the sinkers has not basically changed with individual sinker cams being used at each station and a sinker spring band urges the sinkers inwardly. The individual cams and spring band do not provide positive control of the sinkers because the spring band extends along a straight line path between the innermost and outermost positions of the sinkers and does not engage and control those sinkers between these extreme positions. This lack of positive control of the sinkers permits them to abut against the individual cams and become broken, causing a smash-up which puts the machine out of production for a considerable length oftime.

With the foregoing in mind, it is an object of the present invention to provide sinker control cam means which eliminates the usual sinker spring band and provides positive positioning and control of the sinkers in a fine gauge multifeed circular hosiery knitting machine so as to produce improved hosiery fabric at increased production rates.

In accordance with the positive sinker control of the present invention, the sinkers are each provided with inner and outer operating butts. A single substantially continuous circular sinker cam is supported on the sinker cap and operates to move the sinkers outwardly and then initially move the sinkers inwardly at each knitting station. A separate sinker cam is provided for engaging the outer portion of the outer cam butt of each of the sinkers at each knitting station and to complete the inward movement of the sinkers. The inwardly and outwardly inclined cam surfaces of the continuous sinker cam ring and the separate sinker cams are maintained at a minimum angle so as to gradually move the sinkers and to thereby reduce sinker cam wear and permit faster operation of the machine.

Other advantages, objects and details of the invention will be described in connection with the drawings in which- FIG. 1 is a top plan view of the sinker cap ofa circular multifeed hosiery knitting machine having eight knitting stations;

FIG. 2 is a vertical sectional view taken substantially along the line 2-2 in FIG. 1;

FIG. 3 is a enlarged fragmentary vertical sectional view taken along the line 3-3 in FIG. 1 and showing the parts in a different position from that shown in FIG. 2;

FIG. 4 is a view similar to FIG. 3 taken substantially along the line 4-4 in FIG. 1 and showing the parts in yet another position;

FIG. 5 is a view of the sinker cap removed from the machine and turned over, looking at the lower side thereof;

FIG. 6 is an enlarged vertical sectional view taken substantially along the line 66 and being rotated so that it appears in its normal upright position;

FIG. 7 is a view similar to FIG. 6 but being taken substantially along the line 77 in FIG. 5;

FIG. 8 is an isometric view of one of the individual sinker cams, removed from the sinker cap;

FIG. 9 is a greatly enlarged fragmentary plan view of a portion of the sinker cap at one knitting station with the upper surface of the sinker cap broken away to illustrate the manner in which the sinkers are positively controlled and actuated at each knitting station;

FIG. 10 is an enlarged fragmentary plan view of a portion of the sinker cap and illustrating a modified form of individual sinker cam positioned to operate with the continuous sinker ring; and

FIG. 11 is an isometric view of one of the individual sinker cams, removed from the sinker cap.

The invention is illustrated in connection with the parts of a conventional type of circular multifeed hosiery knitting machine and only those parts of the machine are shown which are necessary to an understanding of the present invention. The invention is illustrated in connection with an eight-feed hosiery knitting machine, however, it is to be understood that the present invention is also applicable to other types of multifeed hosiery knitting machines.

The circular hosiery knitting machine includes a rotatable needle cylinder 10 (FIG. 2) having needles 11 supported for vertical movement in the slots of the needle cylinder 10. The needles 11 are provided with latches 11a which are pivoted in a thickened portion of the needle shank (FIG. 3). A sinker bed 12 is conventionally supported on the upper end of the needle cylinder 10 (FIG. 2) and includes radially extending grooves in which sinkers, broadly indicated at S, are supported for radial sliding movement. A sinker cap 13 is supported on the sinker bed 12 and is prevented from rotating in a conventional manner while the sinker bed 12 rotates with the needle cylinder 10 so that the sinkers operate between and rotate with the needles 1]. The sinkers and needles cooperate in the usual manner in the formation of stitch loops when yarn is fed to the needles and they are lowered to stitch-forming level at each knitting station.

The sinker cap 13 is usually provided with a plurality of individual sinker cams at each knitting station for imparting inward and outward radial movement to the sinkers S. A spring band, not shown, is normally provided to resiliently urge the sinkers S inwardly as they move by the .individual cams. In ac cordance with the present invention, this conventional spring band has been eliminated and novel sinker cams to be presently described, are supported in the sinker cap 13.

Each sinker S (FIGS. 3 and 4) is provided with an inner operating butt 20 and an outer operating butt 21 which in cludes respective inner and outer cam engaging surface 22, 23. A throat 25 and nib 26 are provided on the inner portions of each of the sinkers S.

First sinker cam means in the form ofa single, substantially continuous circular sinker cam, broadly indicated at R, is supported on the lower surface of the inner peripheral edge portion of the sinker cap 13 by means of screws 30 and nuts 31 which pass through aligned holes in the sinker cam R and the sinker cap 13. At one point in the cam R, a narrow transverse sinker removal slot 32 (FIG. 5) is provided. It is to be noted that the width of the sinker cam R is reduced in that leading portion adjacent the transverse slot 32 and in the direction of movement of the sinkers S. The width of the sinker cam R is reduced to prevent abutment of adjacent sinker portions when passing the transverse slot 32. This slot 32 is aligned with a wider slot 33 in the sinker cap and a sinker gate plate 34 is suitably secured therein. This slot and. gate arrangement is provided for removal of and replacement of broken sinkers, in the usual manner.

The positions of the individual knitting stations of the knitting machine are indicated by the'outwardly peaked portions of the cam R, as indicated by the numerals I through VIII in FIGS. 1 and 5. The configuration of the portions of sinker cam R adjacent each of the knitting stations I through VIII is identical to control the operation of the sinkers S in an identical manner at each of these knitting stations, to be presently described.

Second sinker cam means in the form of a separate individual sinker push-in or end cam 40 is supported for radial adjustment at each knitting station and just past the outermost peaked portions of the cam R (FIG. 9). Each separate sinker cam 40 is supported in a radial groove 42 which is cut in the lower surface of the sinker cap 13 and extends outwardly to the downwardly depending peripheral rim thereof. Each sinker cam 40 is supported in the groove 42 and on the sinker cap 13 by a screw 45 and a nut 46 which pass through aligned holes in the cam 40 and the sinker cap 13. The hole in the sinker cam 40 is preferably counter-bored so that the head of the screw 45 is substantially flush with the lower surface of the cam 40 (FIG. 6). The hole in the sinker cap 13 is preferably elongated, as illustrated in FIG. 6, so that the cam 40 may be radially adjusted, relative to the cam R.

The screw and nut means securing the single cam R and the individual earns 40 to the sinker cap 13 provides a substantial savings in manufacturing costs. The conventional types of sinker cams are drilled and tapped and a screw is threaded directly into the cams. It is much more expensive to drill and tap cams than to singly drill a hole therein, in accordance with the present invention.

The manner in which the sinkers S are moved outwardly and inwardly at each of the knitting stations is very critical and the thickness of the single cam R, is relative to the distance between the inner operating butt and the inner cam engaging surface 22 of the outer butt 21 of the sinker S, must be maintained within very close limits. As has been stated, the configuration of the cam surface at each knitting station is identical and the cam surface of the cam R at the station H, illustrated in FIG. 9, will be described in detail.

The portion of the cam R extending between the dash-dot line a and the dash-dot line b is substantially the same width or thickness as the distance between the inner butt 20 and the inner cam engaging surface 22 of the outer butt 21, as shown in FIG. 3, so that the sinker S is positively maintained in the innermost position shown in FIG. 2, relative to the needles 11. As the needles and sinkers approach the knitting station, the needles are raised to a clearing level wherein the loops surrounding the shanks of the needles are disposed below the lower ends of the latches and the nibs of the sinkers 26 exert inward pressure against the fabric.

As the sinkers S move between the dash-dot line I: and the dash-dot line c, the cam R gradually moves the sinkers outwardly as the inner cam engaging surfaces of the butts 21 engage the outer cam surface of the cam R, until the sinkers are successively moved to the outermost position shown in FIG. 3 where the nib 26 is outside of the needle 11. During this movement between the dash-dot line b and c, the needles 11 are beginning to be lowered by the conventional stitch cam, after having picked up a yarn in their hooks. As the needles are lowered, the latch of the needle is closed by the loop held on the shank so that it closes on the yarn picked up in the hook, as illustrated in FIG. 3. The sinkers S are gradually moved outwardly between the dash-dot lines 12 and c by the outer portion of the cam R which is inclined outwardly at an angle of approximately 15.

Between the dash-dot lines 0 and d, the sinkers S are initially moved inwardly by the inner cam surface of the cam R engaging the inner butts 20. This portion of the cam R is inclined inwardly at an angle of approximately As the sinkers are moving from the dash-dot line c to the dash-dot line d, the needles 11 are being drawn down further by the stitch cam the lowest point of which is aligned with the dash-dot line d in FIG. 7, to a stitch loop forming level and a stitch loop is formed as the hook is lowered below the throat 25 of the sinker 5.

Further inward movement is imparted to the sinker S as it moves between the dash-dot lines d and e by engagement of the outer cam engaging surface of the outer butt 21 with an inwardly inclined cam surface on the inner portion of the separate cam 40. This inwardly inclined cam surface is steeper than the inner cam surface on the cam R, and is inclined inwardly at approximately Since this separate cam is radially adjustable, it may be accurately adjusted to determine the innermost depth to which the sinkers are projected at each knitting station and the adjustment between adjacent knitting stations may be set so that each knitting station forms stitch loops of exactly the same length and no rings or streaks are formed in the fabric. These rings are usually caused by a certain course being knit with longer stitches than an adjacent course. When the sinker S is moved to its innermost position by the cam 40, the corresponding needle is raised slightly so that the loop cast from the hook is held in an innermost position.

As soon as the sinker S moves beyond the free end of the cam 40, at the location of the dash-dot line 2, its outer butt 21 is no longer engaged and urged inwardly by the cam 40. At this point, the inner portion of the cam R is provided with an inwardly curved portion 50 (FIG. 9) so that the sinker S is free to move outwardly a slight amount. This slight outward movement relieves the inward pressure on the stitch loop which has just been formed. This slight outward movement of the sinker occurs at the precise time that the thickened portion of the needle 11 which contains the pivot point of the latch is moving upwardly through the stitch loop and this relieves the strain on the yarn and the stitch loop as this thickened portion of the needle and the latch moves upwardly. This stitch strain relieving feature provided by the inwardly curved portion 50 permits very small stitch loops to be formed when knitting the ankle portion of the hosiery because these very small stitch loops are not strained and the yarn is not cut as the thickened pivot portion of the needle passes upwardly therethrough.

As the sinkers and needles move beyond the dash-dot linef, they are again held in an innermost position and the needles have been raised to the uppermost position shown in FIG. 2 to clearing level. The stitch loops are held inwardly against the shank of the needle and below the tip of the latch so that the loop passes upwardly behind and inside of the lower tip of the latch as the needle begins to lower as it approaches the next knitting station.

The sinkers are thus positively controlled at each of the knitting stations I through VIII and are drawn outwardly in a gradual manner by the cam R engaging the inner cam engaging surface 22 of the outer butt 21. The sinkers are initially moved inwardly by engagement of the inner butt 20 with the inner surface of the cam R and then the inward movement of the sinkers is completed by engagement of the outer cam engaging surface of the outer butt 21 with the separate sinker cam 40. Since the sinkers are initially moved inwardly by engagement of the inner butt 20, there is less danger of bending the very thin sinker than there would be if the inward movement were imparted to the sinker by engagement with its outer cam engaging surface 23 of the outer butt 21. I

In the modification shown in FIGS. 10 and 11, the parts are identical, except that the separate sinker cams have been modified slightly. Therefore, corresponding parts which correspond with parts of the invention shown in FIGS. 1-8 will bear like reference characters with prime notations added. The cam R is identical to the cam of the first form of invention and each separate sinker cam 40' has been modified by the addition of a wing extension 51 (FIG. 11). The main body of the cam 40 is still the same width as and is supported for radial adjustment in the radial groove 42 in the sinker cap 13. The wing portion 51 is off-set so that its upper surface lies against the lower surface of the sinker cap 13. As will be noted in FIG. 11, the wing portion 51 extends beyond the groove 42 and is in alignment with the curved portion on the cam R. This wing portion 51 is at substantially the same level as the inner portion of the main body of the inclined surface on the cam 40' and maintains engagement with the outer cam surface 23 of the outer butt 21 of the sinkers as they move beyond the groove 42 so that the sinker is not relieved but is maintained in an innermost position.

In either embodiment, the sinker is gradually withdrawn at each knitting station by the single cam R, initially moved inwardly at a slight angle by the cam R engaging the inner butt 20 and then finally moved inwardly to its innermost position by engagement of the separate cam 40 with the outer cam surface 23 of the outer butt 21 of the sinker. This positive control of the sinkers and the elimination of the sinker band, provides the required amount oftension on the stitch loops by the nibs 26 of the sinkers so that the fabric is uniformly formed with stitch loops which are not distorted and stretched or drawn with undue tension and a clearer fabric is formed without streaks or rings.

In the drawings and specification, there has been set forth a preferred embodiment of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes oflimitation.

What is claimed is:

I. In a circular hosiery knitting machine for the manufacture of fine gauge ladies hosiery including a rotatable needle cylinder, needles supported for vertical movement in said cylinder between a high clearing level and a lower stitch loop forming level, a plurality of yarn feeding and knitting stations spaced apart around said needle cylinder, a sinker cap supported around said needle cylinder, and sinkers supported for radial movement between the needles and cooperating therewith in the formation of stitch loops, the combination therewith of a. inner and outer operating butts on each of said sinkers,

said outer butts including inner and outer cam engaging surfaces,

b. first sinker cam means supported on said sinker cap and adjacent each knitting station, said first sinker cam means being positioned above said sinkers and between said inner and outer butts and being of substantially the same width as the distance between said inner and outer butts of said sinkers, said first sinker cam means being shaped for drawing the sinkers outwardly by engagement with said inner cam engaging surface of said outer butt as said needles start to move downwardly from the high clearing level and for then initially moving said sinkers inwardly by engagement with said inner butt as said needles complete their downward movement to the stitch loop forming level, and

. second sinker cam means supported on said sinker cap and adjacent each knitting station, each of said second sinker cam means being positioned to engage said outer cam engaging surface of said outer butt to complete the inward movement of said sinkers at each knitting station as said needles are raised slightly from the stitch loop forming level.

2. In an apparatus according to claim 1 wherein said first sinker cam means comprises a single, substantially continuous circular sinker cam ring provided with a relatively narrow transverse slot to facilitate removal and replacement of sinkers.

3. In an apparatus according to claim 2 wherein the width of said sinker cam ring is reduced in that leading portion adjacent the transverse slot and in the direction of movement of said sinkers, the width of said sinker cam ring being reduced to prevent abutment of adjacent sinker portions when passing the transverse slot therein.

4. In an apparatus according to claim 2 including screw and nut means securing said substantially continuous sinker cam ring to said sinker cap to thereby eliminate drilling and tapping either said sinker cam or said sinker cap.

5. In an apparatus according to claim 1 including screw and nut means connecting each of said second sinker cam means to said sinker cap.

6. In an apparatus according to claim 1 wherein said sinker cap has a radially extending groove cut in the lower surface and at each knitting station, and wherein at least a portion of said second sinker cam means is supported in said groove.

7. In an apparatus according to claim 6 including means supporting said second sinker cam means in said groove for longitudinal adjustment along said groove.

8. In an apparatus according to claim 7 wherein the width of said second sinker cam means corresponds to the width of said groove.

9. In an apparatus according to claim 7 wherein said second sinker cam means includes a portion corresponding in width to and positioned in said groove and a portion extending outwardly beyond said groove.

10. In an apparatus according to claim 2 wherein that portion of said substantially continuous circular sinker cam ring for drawing said sinkers outwardly by engagement with said inner cam engaging surface of said outer butt is inclined outwardly at an angle of 15 to gradually move the sinkers outwardly.

11. In an apparatus according to claim 2 wherein that portion of said substantially continuous circular sinker cam ring for initially moving said sinkers inwardly by engagement with said inner butts is inclined inwardly at an angle of approximately 25 to initially move the sinkers inwardly at a relatively slow rate.

12. In an apparatus according to claim 1 wherein that portion of said second sinker cam means for completing the inward movement of said sinkers at each knitting station is inclined inwardly at an angle of approximately 35.

13. In an apparatus according to claim 1 wherein said first sinker cam means includes an inwardly curved cam surface on the inner portion thereof and at each knitting station, said inwardly curved cam surface being positioned immediately adjacent that portion adapted to initially move said sinkers inwardly, said inwardly curved cam surface extending beyond the point where said second sinker cam means moves said sinkers inwardly to complete their inward movement, and said inwardly curved cam surface permitting slight outward movement of the sinkers immediately after their innermost movement by said second sinker cam means to relieve inward pressure of the loop on the needle as the needle raises and the loop passes downwardly over the thickened portion of the needle which provides the pivotal connection of the latch to the needle. 

1. In a circular hosiery knitting machine for the manufacture of fine gauge ladies'' hosiery including a rotatable needle cylinder, needles supported for vertical movement in said cylinder between a high clearing level and a lower stitch loop forming level, a plurality of yarn feeding and knitting stations spaced apart around said needle cylinder, a sinker cap supported around said needle cylinder, and sinkers supported for radial movement between the needles and cooperating therewith in the formation of stitch loops, the combination therewith of a. inner and outer operating butts on each of said sinkers, said outer butts including inner and outer cam engaging surfaces, b. first sinker cam means supported on said sinker cap and adjacent each knitting station, said first sinker cam means being positioned abovE said sinkers and between said inner and outer butts and being of substantially the same width as the distance between said inner and outer butts of said sinkers, said first sinker cam means being shaped for drawing the sinkers outwardly by engagement with said inner cam engaging surface of said outer butt as said needles start to move downwardly from the high clearing level and for then initially moving said sinkers inwardly by engagement with said inner butt as said needles complete their downward movement to the stitch loop forming level, and c. second sinker cam means supported on said sinker cap and adjacent each knitting station, each of said second sinker cam means being positioned to engage said outer cam engaging surface of said outer butt to complete the inward movement of said sinkers at each knitting station as said needles are raised slightly from the stitch loop forming level.
 2. In an apparatus according to claim 1 wherein said first sinker cam means comprises a single, substantially continuous circular sinker cam ring provided with a relatively narrow transverse slot to facilitate removal and replacement of sinkers.
 3. In an apparatus according to claim 2 wherein the width of said sinker cam ring is reduced in that leading portion adjacent the transverse slot and in the direction of movement of said sinkers, the width of said sinker cam ring being reduced to prevent abutment of adjacent sinker portions when passing the transverse slot therein.
 4. In an apparatus according to claim 2 including screw and nut means securing said substantially continuous sinker cam ring to said sinker cap to thereby eliminate drilling and tapping either said sinker cam or said sinker cap.
 5. In an apparatus according to claim 1 including screw and nut means connecting each of said second sinker cam means to said sinker cap.
 6. In an apparatus according to claim 1 wherein said sinker cap has a radially extending groove cut in the lower surface and at each knitting station, and wherein at least a portion of said second sinker cam means is supported in said groove.
 7. In an apparatus according to claim 6 including means supporting said second sinker cam means in said groove for longitudinal adjustment along said groove.
 8. In an apparatus according to claim 7 wherein the width of said second sinker cam means corresponds to the width of said groove.
 9. In an apparatus according to claim 7 wherein said second sinker cam means includes a portion corresponding in width to and positioned in said groove and a portion extending outwardly beyond said groove.
 10. In an apparatus according to claim 2 wherein that portion of said substantially continuous circular sinker cam ring for drawing said sinkers outwardly by engagement with said inner cam engaging surface of said outer butt is inclined outwardly at an angle of 15* to gradually move the sinkers outwardly.
 11. In an apparatus according to claim 2 wherein that portion of said substantially continuous circular sinker cam ring for initially moving said sinkers inwardly by engagement with said inner butts is inclined inwardly at an angle of approximately 25* to initially move the sinkers inwardly at a relatively slow rate.
 12. In an apparatus according to claim 1 wherein that portion of said second sinker cam means for completing the inward movement of said sinkers at each knitting station is inclined inwardly at an angle of approximately 35*.
 13. In an apparatus according to claim 1 wherein said first sinker cam means includes an inwardly curved cam surface on the inner portion thereof and at each knitting station, said inwardly curved cam surface being positioned immediately adjacent that portion adapted to initially move said sinkers inwardly, said inwardly curved cam surface extending beyond the point where said second sinker cam means moves said sinkers inwardly to complete their inward movement, and said inwardly curved cam surface permitting slight outward movement of the sinkers immediately after their innermost movement by said second sinker cam means to relieve inward pressure of the loop on the needle as the needle raises and the loop passes downwardly over the thickened portion of the needle which provides the pivotal connection of the latch to the needle. 